Well treating apparatus



Oct. 12, 1965 Filed May 28, 1963 CHART RECORDER L. B. THIESSEN ETAL WELLTREATING APPARATUS FLUID SUPPLY TANK TIMER MEANS 5 Sheets-Sheet l FIG-3INVENTORS LAWRENCE B. THIESSEN HARRY J. KIPPS ATTORNEYS 1965 L. B.THIESSEN ETAL 3, 5

WELL TREATING APPARATUS Filed May 28, 1963 5 Sheets-Sheet 2 WELLTREATING FLUID SUPPLY TANK TIMER MEANS IN V EN TORS LAWRENCE B. THIESSENBY HARRY J. KIPPS ATTORNEYS,

1965 B. THIESSEN ETAL 3,211,225

WELL TREATING APPARATUS 5 Sheets-Sheet 3 v I w I INVENTORSLAWRENGEB.THIE$3EN HARRY J. KIPPS war/Q Filed May 28, 1963 W258 @123: E:m 52; $32 22; 5!: H .3 ix

ATTORNEYS United States Patent 3,211,225 WELL TREATING APPARATUSLawrence B. Thiessen, Garden Grove, and Harry J. Kipps, Whittier,Caliti, assignors to Signal Oil and Gas Company, Los Angeles, Calif.

Filed May 28, 1963, Ser. No. 283,817 6 Claims. ((1 166-75) The presentinvention generally relates to well treating and more particularlyrelates to improved apparatus for carrying out the treating operation.

Many wells such as oil wells require the frequent application thereto ofvarious treating solutions in order to keep the wells clear and tomaximize production of fluids therefrom, e.g. oil and the like. In thisregard, various chemical solutions are utilized to control oil wellcorrosion, minimize deposition of paraflins, carbonates, gypsum scale,etc. and to prevent the agglomeration of asphaltenes, Chemical solutionsare also frequently added to oil wells for various other generallysimilar purposes.

Such chemicals are usually added to the wells on a regular schedule, inmost instances through the use of suitable portable pumping equipmentand the like moved from well to Well according to the treating schedule.Thus, an operator is required to periodically visit and service eachwell in turn, carrying along with him the necessary portable welltreating equipment. Such a procedure is necessarily relativelyexpensive.

Various types of apparatus have been devised to eliminate the necessityof having an operator travel from well to well to carry out the welltreating procedure. In this regard, where a number of wells are closelygrouped together, it becomes economically feasible to employ arelatively complicated automatic well treating system which periodicallypumps well treating solutions to each of the closely grouped wells.However, such systems are initially relatively expensive, of the orderof $10,000 or more, and cannot be economically employed where the wellsare dispersed over a considerable area, or where only one or a few wellsare involved. Furthermore, much of such multiple well treatingapparatus, due to its complicated nature, is subject to maintenanceproblems, including corrosion and the like. Pumps are usuallyincorporated in such apparatus and are especially subject to corrosionand also leakage of well treating fluids.

A further problem sometimes encountered in multiple treating systems isa variation in the pressure between individual wells of the group to betreated. Certain wells may be at about atmospheric or atsuperatmospheric pressure while others may be at subatmosphericpressure. This tends to complicate and diversify the equipment neededfor multiple well treatment.

Accordingly, it would be desirable to provide improved well treatingapparatus capable of economical automatic operation on individual wells,such as oil wells. Such equipment should be simple and inexpensive toinstall and to maintain. Moreover, it should preferably have a highsafety factor, i.e. be essentially explosion proof, so that it can beinstalled in close proximity to the well. In addition, it should becapable of repeatedly delivering predetermined volumes of well treatingfluid over long periods of time and without leakage or malfunction.

Accordingly, it is a primary object of the present invention to provideimprovements in well treating.

It is also an object of the present invention to provide improvedapparatus for automatically treating an individual oil well.

It is also an object of the present invention to provide improvedapparatus capable of automatically intermittently treating an oil wellwith fluid, which apparatus is simple, inexpensive, corrosion resistant,and essentially leak-proof and explosion-proof.

It is a still further object of the present invention to provideimproved apparatus for automatically delivering predetermined volumes ofwell treating solution to wells, such as oil wells, which Wells may beat atmospheric, superatmospheric or subatmospheric pressure.

The foregoing objects are accomplished by providing the present welltreating apparatus for the treating operation. The operation includesautomatically passing a predetermined volume of well treating fluid intoa pressure responsive injection zone and then exerting controlledpressure on said zone to reduce the volume of the zone and to force thewell treating fluid from said zone into the annulus of an oil well, inresponse to such volume reduction of the injection zone. Further .inaccordance with the present operation, pressure is then relieved on theinjection zone so as to allow the Zone to return to its initial volume,whereupon a further charge of well treating fluid is passed to theinjection zone for passage to the well annulus at a predetermined time.

In the present operation, a well treating fluid injection zone orchamber is disposed within container means. A pressure responsive meansadapted to vary the volume of the injection chamber or zone forms a partof said zone within the container means. Suitable conduits interconnectcomponents of the system, and fluid passage therethrough is controlledby valve means which may be actuated by timer means providing timedelectrical circuit operating pulses. Periodic collapsing or volumereduction of the injection zone or chamber is effected by pressureexerted on the pressure responsive means through a pressure-impartingfluid, such as water or gases, passed into contact therewith. Moreover,pressure-imparting fluid may mix with the well treating fluid externalof the container means so as to sweep the well treating fluid toward thewell annulus. The pressure-imparting fluid may be a single fluid ormultiple fluids introduced into the system at selected locations.

In the event that the well has a higher pressure than that of the wateror other pressure-imparting fluid, a pressure equalizing zone isprovided between the injection zone and the well annulus. Pressure onwell treating fluid disposed in the pressure equalizing zone is adjustedto that of the well in order to allow the easy passage of the welltreating fluid into the well.

With such an apparatus, predetermined volumes of a well treating fluid,such as a thioether solution adapted to minimize agglomeration ofasphaltenes, can be automatically passed at predetermined timedintervals into the well to treat the same without human intervention. Asan example, 500 cc. amounts of a thioether solution can be automaticallydelivered to a well annulus by the described apparatus every six hoursfor a period of several weeks without leakage of the equipment andwithout human manipulation or intervention.

The apparatus is relatively simple and inexpensive to initially provideand to maintain and yet provide effective automatic control of a wellover long periods of time by the delivery of predetermined volumes ofchemical well treating fluid to the well on a regular schedule of spacedinjections.

Further advantages of the present invention will be apparent from astudy of the following detailed description and the accompanyingdrawings of which:

FIG. 1 is a schematic flow diagram of a first embodiment of apparatusadapted to carry out the present method for the fluid treatment of awell having a pressure less than that provided by pressure-impartingfluid utilized in the appaaratus;

FIG. 2 is a schematic flow diagram of a second embodiment of apparatusadapted to carry out the present method for fluid treatment of a wellhaving a pressure greater than that of the pressure-imparting fluidutilized in the apparatus;

P16. 3 is an enlarged schematic illustration of one embodiment of theinjection tank utilized in the apparatus of FIGS. 1 and 2, a portionbeing broken away to illustrate the internal construction thereof; and

FIG. 4 is a schematic flow diagram of a third embodiment of simplifiedapparatus adapted for the fluid treatment of a well.

Now referring more particularly to FIG. 1 of the accompanying drawings,a schematic flow diagram is illustrated, which diagram depicts apparatus6 adapted for use in carrying out the method of the present invention.The apparatus 6 is particularly suitable for the fluid treatment ofindividual oil wells wherein the pressure of such wells is less than thepressure of a pressure-imparting fluid utilized in the apparatus.

Referring particularly to FIG. 3 of the drawings, a container means orinjection tank 8 is illustrated, which includes a variable-volume welltreating fluid injection zone 10, in part defined by a pressureresponsive means 12 also disposed within the container 8. The means 12comprises a resilient flexible diaphragm separating the zone 10 from theremainder of the container 8. The diaphragm is adapted to vary thevolume of the injection zone 10 in response to fluid pressure. Otherforms of pressure responsive means comparable in function to means 12can be utilized in place thereof, for example a transverse rigid wall orplate (not shown) slidable within the container 8 and sealed againstby-passing of fluid around the periphery thereof. Such a plate could befitted with means, such as a spring, etc. (not shown) adapted to returnthe plate to an initial position, e.g. to a position maximizing thevolume of the injection zone 10. In other Words, such spring could biassuch plate against an injection zone 10 volume reduction i.e. byexerting pressure in a direction opposite to that of thepressureimparting fluid.

The container 8 can be any suitable size and shape, and can beconstructed of any suitable material, for example steel, which isnon-reactive with the well treating fluid. For example, the containermay be two steel shells releasably secured together, with the diaphragm14 disposed therebetween. As shown in FIG. 3, the diaphragm 14 dividesthe container 8 into the variable volume injection zone 10 and a fluidpressure-imparting zone 16. The diaphragm 14 is resilient and flexibleand can move, for example, between the large volume injection zoneposition shown in solid outline in FIG. 3, representing zone 10 in awell treating fluid-filled condition, to the small volume injection zoneposition shown in dotted outline in FIG. 3, representing zone 10 afterthe well treating fluid has been expelled thereform. Movement betweenthe two positions depends on the direction and degree of pressureexerted against the diaphragm 14. The diaphragm 14 can be fabricated ofany suitable material such as natural rubber, or synthetic rubber, suchas neoprene, styrene-butadiene, butyl rubber, Teflon, vinyl,polyethylene, polypropylene or the like resilient stretchable material.

A well treating fluid supply line 18 runs into the container 8,specifically into the injection zone 10 as shown in FIG. 3, from asuitable source of well treating fluid, for example, the vessel 21)shown in fragmentary elevation in FIG. 1 disposed above the container 3so as to provide a hydrostatic head of a well treating fluid for easypassage thereof into the zone 10. A valve 22 may be provided in theline18 to control the flow of well treating fluid to the zone 10. Thevalve 22 is preferably operated by a solenoid 24 connected, as byelectrical line 26, to a timer means 28, for automatically controllingthe opening and closing of the valve 22. The timer means 23 may be ofany conventional construction capable of simultaneously controlling thepassage of electrical current to one or a plurality of solenoids for apredetermined interval of time and at predetermined spaced intervals.Thus, the timer means 28 may be provided with a suitable electricallyoperated settable clock (not shown) or the like. The time means 28 isconnected to a source of electrical current, such as a generator 30, asby lines 32 and 34, which in turn can be powered through a drive shaft36 running from a source of mechanical power, as, for example, the motor38, as shown in FIG. 1. Thus, for example, the motor 38 can be the usualgasoline or kerosene powered small motor adapted to operate well pumpingor drilling equipment or the like. Other arrangements of equipment forproviding electrical current, either alternating or direct, for thetimer means 28 will be obvious to those skilled in the art. Moreover,the timer means may be disposed at a distance from the apparatus andcomprise means for sending a series of timed electrical impulses to thesolenoids, as from a central control station adapted to electricallycontrol the operation of a plurality of the described individual welltreating devices. The timer means 28 or equivalent timer means can beconstructed so that the solenoid operated valves of the apparatus 6 moveto a preselected position at a preselected time when current is passedto the solenoids connected to the valves, after which they move to adifferent position (upon cutting off of current to the solenoidconnected to each valve). Accordingly, timed automatic control of theflow of materials through the fluid lines to which such valves areconnected is provided.

As well treating fluid passes, by gravity, through the line 18 from thetank 20 to the zone 10 with the valve 22 open, the diaphragm 14 isforced down towards the bottom wall 40 of the tank 8, as shown in FIG.3, maximizing the volume of zone 10 in the tank 8. Thereafter, the valve22 is then solenoid operated so as to close, sealing the tank 8 from thetank 20. As explained hereinafter, closing of the valve 22 can bedelayed until ejection of the well treating fluid from the zone It) isdesired.

As shown in FIG. 1, a well treating fluid outlet line 42 interconnectsthe zone 10 with the well 7. The line 42 is provided with a valve 44which is operated by a solenoid 46 and is connected to the timer 28 byan electrical line 48. The valve 44 is kept shut until it is desired toinject the well treating fluid in the zone 10 into the well 7.Preferably, the line 42 runs into a common line 50 into which apressure-imparting fluid outlet line 52 also merges, so that thepressure-imparting fluid can mix with the well treating fluid and propelthe same toward the well 7. The line 52 is connected at the opposite endthereof to the zone 16 of the tank 8, as shown in FIG. 3.

Pressure-imparting fluid, for example water under the usual water mainpressure or force imparted by municipal water pumping systems, passesfrom a fluid pressure source 54 such as a water main or the like,through a pressureimparting fluid inlet line 56 connected at one end tothe source 54 and at the opposite end to the zone 16 of the tank 8.Accordingly, at a preselected time, the pressureimparting fluid such aswater is brought into contact in the zone 16 with the diaphragm 14 andexerts collapsing pressure on zone 16 so as to cause the well treatingfluid in the zone 10 to be expelled therefrom and be passed through theline 42 into the line 50. The pressure-imparting fluid enters the zone16 through the line 56 and exits the zone 16 through the line 52, mixingwith the well treating fluid in the common line 50. The line 56 isprovided with a valve 58 operated by a solenoid 60 connected to thetimer by an electrical line 62. During ejection of well treating fluidsfrom the zone 10, the valve 58 is kept open. So also is the valve 44,while the valve 22 is kept closed. The line 50 is preferably providedwith a valve 64 operated by a solenoid 66 connected to the timer 28 byan electrical line 68. The valve 64 is kept open during ejection of welltreating fluid from the zone 10, so as to allow injection of such fluidinto the well 7, with which the line 50 is connected, as shown in FIG.1.

The valves 58 and 64 are preferably so-called three way valves and arepreferably connected to a line 70 extending therebetween andinterconnecting lines 56 and 50. With such an arrangement, when the welltreating fluid has been injected into the well from the zone 10, asdetermined by a suitable interval of time since movement of the valve 44to the open position, and valves 64 and 54 move to positions opening thelines 50 and 56, respectively, and closing the line 70, then the currentsupply to the respective solenoids is cut off. As a result, the valve 44closes and the valves 64 and 58 adjust (e.g. as by in ternal springsbiasing said valves toward a predetermined position) so as to allowcommunication therebetween i.e. communication between the line 56 andthe line 70 is established at the valve 58 While the passage of fluidfrom the source 54 through the line 56 is blocked. Moreover,communication between the line 50 and the line 70 is established at thevalve 64, while passage of fluid from the line 42 into the well 7 isblocked. The pressure-imparting fluid in the zone 16 is thereby exposedto the lower pressure of the well -7 annulus and is allowed to drainthereinto, as through the line 56 into the line 70 at the valve 58, thenthrough the line 70 into the line 50 at the valve 64, and through theline 50 into the well 7. If desired, the valves 58 and 64 can besolenoid operated so as to automatically adjust, after a suitable periodof time dictated by the timer means 28, that is, after drainage of thepressure-imparting fluid from the zone 16, to a third position blockingboth line 70 and lines 56 and 50, as shown in FIG. 1. Conventionalvalve-operating means can be provided for such purposes.

Drainage of the pressure-imparting fluid from the zone 16 into the well7 allows the pressure responsive means 12, that is, the diaphragm 14 tomove from the position shown in dotted outline to that shown in solidoutline under the influence of a new charge of well treating fluidpassed to the zone from the tank 20 through the line 18. When the valve44 closes, and the valves 58 and 64 change in position in response tocessation of electrical current flow to the associated solenoids, thevalve 22 opens to allow the passage of the new charge of well treatingfluid to the zone 10.

At a preselected time in response to the timer means and when the newcharge in the zone 10 is to be expelled therefrom and injected into thewell 7, the on portion of the cycle begins and the valve 22 closes, thevalve 44 opens and the valves 58 and 64 move to positions blocking theline 70 but allowing the free passage of the pressure-imparting fluid toand from the zone 16 and into the well. The well treating fluid passesinto the well 7 through the line 42, the valve 44 and the line 50, andvalve 7 66, as previously described.

As shown in FIG. 1, means such as a chart recorder 72 which can bepneumatically operated or the like can be connected to the apparatus 6,as by line 74, so as to automatically record the successive injectionsof well treating fluid into the well 7. Thus, when the pneumaticallyresponsive recorder 72 is connected to the line 56, as by the line 74,the variations in fluid pressure in the line 56 are recordable. In thisregard, during the on portion of each cycle, the pressure in the line 56is at a maximum, due to passage of the pressure-imparting fluidtherethrough. During the off part of the cycle, such fluid drains intothe lower pressure well and the pressure in the line 56 drops.Accordingly, the pressure variations in the line 56 accurately portrayeach injection cycle in the apparatus 6.

Accordingly, an improved method is provided for automatically injectingon a predetermined schedule preselected volumes of well treating fluidinto the annulus of a well. Apparatus for oarrying out the method isalso provided. That of FIG. 1 is adapted for repeated and continual usewith a well having a pressure lower than that of the drive fluid orpressure-imparting fluid, such as water, used in the apparatus.

A modification of the apparatus illustrated in the schematic drawing ofFIG. 1 is set forth in FIG. 2. The apparatus 6 of FIG. 2 is adapted forcarrying out the present method on a well having a high pressure, thatis, a pressure higher than that of the pressure-imparting fluid, e.g.,water, used in the apparatus. Components of apparatus 6' illustrated inFIG. 2 which are similar to those of apparatus 6 bear the same numeralsas those of apparatus 6, but also hear a prime designation.

The arrangement of apparatus 6 is essentially the same as that ofapparatus 6, except for the addition of a mixture holding tank '76 whichserves as a pressure equalizing zone. Thus, the line 59 does not passdirectly to the well 7', but instead runs to the tank 76. The top of thetank 76 is connected to a line 78 which runs to the well 7. The line 78is provided with a valve 80 which is operated by a solenoid 82 connectedto the timer means 28' by an electrical line 84. Once the tank '76 isfilled with a mixture of well treating fluid and pressureimpartingfluid, the valve 89 opens to equalize the pressure between the well 7and the tank 76. After the pressure is equalized, the fluid mixturepasses by gravity out of the tank 76 through a line 86 and valve 88 intothe well 7'. The valve 58 is operated by a solenoid 90 connected to thetimer means 28 by an electrical line 92. Since the well '7' is at ahigher pressure than the pressureimparting fluid in the zone 15, duringthe off part of the cycle in the apparatus 6 the pressure-impartingfluid in the zone 15 is removed therefrom not by drainage into the well7, but by drainage to a point external of the system, as through line56', valve 53 and line 94 exposed to the atmosphere. Such fluid can alsoexit the apparatus 7 through line 52, valve 50' and line 96 connectedthereto and exposed to the atmosphere.

During the on part of the cycle, the valve 58' is adjusted so that theline 94 is blocked and the line 56 is open from the pressure source 54'.The pressure-imparting fluid flows from the source 54 through the valve58 and through the line 56' into the zone 16', expending that zone byforcing the diaphragm 14' up, thereby reducing the volume of zone It)and forcing the well treating fluid therein out of the line 42, throughthe valve 44 (which during this portion of the cycle is open while thevalve 22 is closed) and into the line 50. In the line 50, the welltreating fluid mixes with pressure-imparting fluid passed theretothrough the line 52 from the zone 16, the mixture passing through thevalve 64 and the line 50' into the tank 76, the line 96 being closed.After the tank 76 is filled or after a suitable interval of time, ascontrolled by the timer means 28, the valve 44' closes and the valve 22'opens, while the valve 58' moves to a position blocking fluid from thesource 54' and opening the line 94 into communication with the line 56.Simultaneously, the valve 64 moves to a position such that the line 96opens into communication with the line 50' and the lines 42' and 52 butpassage of fluid through the line 50 into and out of the tank 76 isblocked.

Thus, the pressure-imparting fluid drains from lines 96 and 94 while thewell treating fluid passes to the zone 10, filling and expanding thesame. Simultaneously, the valve 80 opens and pressure between the well7' and the tank 86 is equalize-d through the line 78, whereupon themixture in the tank 76 passes into the well 7' through the line 86,valve 83 being opened simultaneously with the valve 80. After a suitabletimed interval, the valve 88 closes, and the valve 86 also closes.Alternatively, the valve 80 can be adapted to move to a position closingaccess of fluid to the well 7 through line 78 but opening the tank 76 tothe atmosphere to facilitate subsequent filling of the same in the nextcycle. The chart recorder 72' and line 74' are connected to theapparatus 6' so as to record each such injection cycle as it occurs.

It will be understood that the apparatus 6 can be operated to provide anon cycle portion in which the well treating fluid in the zone 1% ismoved to the tank 76 after mixing With the water or pressure-impartingfluid, and an ofl portion, in which the mixture in tank 76 is passed tothe well 6', in which the Zone 10 is refilled with well treating fluidand in which the pressure-imparting fluid is drained from the zone 16and out of the apparatus.

It will be further understood that other arrangements of equipment canbe utilized for carrying out the present method. Thus, additionalvalves, lines and the like can be disposed in the apparatus 6 and/or 6,as desired. Moreover, components equivalent in function to thosedescribed can be employed in the apparatus 6 and/or 6' or in a similarapparatus. For example, the present method can be effectively carriedout utilizing a plurality of pneumatic-mechanical operated valvescontrolled by a single solenoid operated valve actuator. Gas can be usedto actuate the actuator and to force the well treating fluid from thechemical proportioning chamber. Such an arrangement is illustrated inFIG. 3 of the accompanying drawings.

As shown in FIG. 3, a simplified well treating device 6" is provided.Components of the device 6 which are similar to those of device 6(FIG. 1) bear the same numerals but also a double prime designation. Thedevice 6 includes a supply tank 2t)" and supply line 18 running to achemical fluid injection tank 8'', the line 18 being provided with amechanically operated valve 22". The tank 8 is constructed internallysubstantially identically to that of the tank 8. A fluid pressure sourcesuch as a pressurized gas line 54" runs to a solenoid operated three wayvalve 58" and fluid passes therethrough to the tank 8" by Way of a line56". The line 56 is connected, as by a line 100, with one side of acylinder or piston valve 102, as shown in FIG. 4. The opposite side ofthe valve 102 is connected to the solenoid valve as by a line 104. Thevalve 102 includes a piston 106, a stem 108 of which extends from oneend of the valve 162 and mechanically connects with the lever arms ofthe twoway mechanical valves 22", 110, 44 and 64 to operate all four ofsuch valves simultaneously.

The on portion of the treatment cycle, during which well treating fluidin the tank 3" passes to a well annulus 7", is initiated by pulsing asignal from a timer means 28" through an electrical line 62 to asolenoid 60 connected to the valve 58 to allow fluid from the source 54to pass through the line 100 into the cylinder valve 102, driving thepiston to the position illustrated in FIG. 4 and thereby simultaneouslyclosing the valves 22" and 110 and opening the valves 44-" and 64". Thefluid from source 54" passes through the line 56 into the bottom of thetank 8" and causes expulsion of well treating fluid therefrom in themanner described for the operation of devices 6 and 6, the well treatingfluid passing from the tank 8" through a line 42", the valve 44" and aline 58" running to the well annulus 7". In line 50" the well treatingfluid merges with a second pressure-imparting fluid, for example water,passing thereinto from a water main 112, a line 114- and the valve 64".It will be understood that another pressure-imparting fluid instead ofWater can be used to mix with and sweep the well treating fluid into thewell annulus 7 from the line '56".

After suitable intervals of time, as controlled by timer meanselectrical pulses, the solenoid 60" is shut off, and the valve 58" movesto a position (as by a spring, etc.) which closes off the line 56" andallows the pressure-imparting fluid to pass through the line 104 to thevalve 102, driving the piston 106 to the position shown in dottedoutline in FIG. 4, so as to simultaneously close the valves 44 and 64"and open the valves 22." and 110. Accordingly, well treating fluid nowpasses from the supply tank Ztl" through the line 18" and open valve 22into the tank 8", filling the same. The pressureimparting fluid exitsthe bottom part of the tank 8 through an outlet line 52", the open valve110 and a line 96' communicating with the atmosphere. The system is nowready for a further injection of a predetermined volume of well treatingfluid into the well annulus 7".

The simplified system 6" functions with only a single solenoid operatedthree-way valve. The mechanical twoway valves and the cylinder valve arerelatively inexpensive. Moreover, if'the timer means 28 comprises acontrol remote electrical signal sending station capable of operating aplurality of the systems 6 simultaneously, a further reduction in costof the system 6" occurs.

It will be understood that the present method and apparatus are capableof delivering all types of well treating fluids, both gases and liquids,the latter including dispersions, solutions and the like, inpredetermined volumes into wells which are at superatrnospheric,atmospheric or subatmospheric pressure. The following example furtherillustrates certain features of the present invention.

Example An oil well treating apparatus, constructed substantially as setforth in FIGS. 1 and 3 and employing water at normal water main pressureas the pressure-imparting fluid, was used to deliver automaticallysuccessive charges of about 600 cc. each of a corrosion and scaleinhibitor comprising a mixture of amines and polyphosphates as a welltreating fluid to an oil well operating at a pressure lower than that ofthe water. The apparatus employed a steel cylinder having a neoprenerubber diaphragm 14 dividing the interior thereof to provide aninjection zone 10. Polyethylene tubing was used for the water and welltreating fluids lines. The electrical lines were sealed inexplosion-proof condulets (conduits), as was the electrically operatedclock timer 28. A sealed generator was connected by explosion-proofcondulets to the timer and to sealed solenoid valves. A key-wound(Weekly) pneumatic pressure chart recorder was connected to the waterinlet line 56 upstream of the zone 16. A 53 gallon well treating fluidsupply tank was used to supply the zone 10 with the well treating fluid.With such apparatus, a total of two charges of about 600 cc. each ofcorrosion and scale inhibitor well treating fluid were deliveredautomatically to the well daily for a period of ten months. The chartrecorder was examined and rewound weekly.

The recorder clearly indicated that all 14 charges of well treatingfluid were delivered on schedule to the well each week without humanintervention. Due to the sealed nature of the electrical system, theapparatus 6 was considered essentially explosion-proof and was installedwithin 15 feet of the oil well. Maintenance costs of the apparatusduring the test period were essentially nil. The apparatus continued tooperate satisfactorily without leaking or malfunction throughout thetest period.

Later tests indicated that the apparatus was equally well adapted foruse in the treatment of oil wells with other types of well treatingfluids, including corrosion inhibitors such as selected amines, scalepreventatives and removers, such as selected chromates, polyphosphatesand the like, and dehydration chemicals.

The preceding example clearly illustrates various advantages of themethod and apparatus of the invention. The method is simply andeffective. The apparatus specified in the example is relativelyinexpensive compared to other automatic well treating equipment.Moreover, maintenance and labor costs are very low in contrast to thosewhen each well is conventionally periodical 1y treated by manuallyoperated portable apparatus.

The present apparatus is light weight, simple and effective. It can bemade essentially leak-proof and explo' sion-proof at low cost and iseasy to repair. The apparatus is adapted to incorporate an optionalrecording means which automatically keeps an accurate record of theefficiency of operation of the apparatus and the number of injectionstaking place in a given period of time. The timing means for operatingthe solenoid controlled valve or valves of the apparatus can be simple,efiicient and durable, and either integral with or interconnected withthe apparatus. The apparatus is also adapted for the delivery of anysuitable well treating fluid in any desired amounts and in accordancewith any desired schedule. The pressure-imparting fluid can be anysuitable gas or liquid. Moreover, the present method is equally applicable, with minor modifications of apparatus, to individual wellsoperating at superatmospheric, atmospheric or subatmospheric pressure.set forth in the foregoing.

Although particular arrangements of well treating apparatus andparticular manners of practicing the method of the present inventionhave been set forth, it will be understood that various modifications,changes, additions and substitutions can be made in the apparatus andthe steps of the method. All such modifications, changes additions andsubstitutions in the method and apparatus are within the scope of theappended claims and are a part of the present invention.

What is claimed is:

1. Improved oil well treating apparatus, which apparatus comprises, incombination, container means which includes a single variable volumeWell treating fluid injection chamber, pressure responsive means forminga part of said chamber in said container means and adapted to vary thevolume of said chamber in response to pressure variations, a welltreating fluid supply line interconnecting said injection chamber .and awell treating fluid source, valve means controlling the passage of welltreating fluid from said source to said injection chamber, a welltreating fluid outlet line interconnecting said chamber and the annulusof a well to be treated with said well treating fluid, valve meansdisposed in said well treating fluid outlet line between said injectionchamber and said well annulus, a first pressure-imparting fluid inletline interconnecting said pressure responsive means and a pump-freesource of pressure-imparting fluid external of said well, valve meansdisposed in said first pressureimparting fluid inlet line between saidpressure responsive means and said source of pressure-imparting fluid, apressure-imparting fluid outlet line connected to said pressureresponsive means and fluid pressure relief means connected to saidpressure responsive means whereby pressure-imparting fluid in contactwith said pressure responsive means can be moved out of contacttherewith so as to reduce pressure imparted to said pressure responsivemeans, a second pressure-imparting fluid inlet line interconnecting apump-free source of fluid pressure and said well treating fluid outletline external of said container means, whereby said well treating fluidis contacted with pressure-imparting fluid and is thereby urged towardsaid well annulus, and valve means disposed in said secondpressure-imparting fluid inlet line, and timer means interconnected tosaid valve means and to said fluid pressure relief means and adapted tointermittently activate the same, whereby the intermittent injection ofa predetermined volume of said well treating fluid into said annulus iseffected.

2. The apparatus of claim 1 wherein said valve means disposed in saidfirst pressure-imparting fluid inlet line comprises a solenoid-actuatedvalve interconnected with said timer means, wherein a mechanical valveactuator is operably connected to said solenoid-actuated valve in turnmechanically connected to each of said fluid pressure relief means andsaid remaining valve means.

3. Improved oil well treating apparatus adapted to be operated at apressure higher than that of the annulus of a well to which theapparatus is to be connected, which apparatus comprises, in combination,container means which includes a single variable volume well treatingfluid injection chamber, pressure responsive means forming a part ofsaid chamber in said container means and adapted to vary the volume ofsaid chamber in response to pressure variations, a well treating fluidsupply line Further advantages are as interconnecting said injectionchamber and a well treating fluid source, valve means controlling thepassage of well treating fluid from said source to said injectionchamber, a well treating fluid outlet line interconnecting said chamberand the annulus of the well to be treated with said well treating fluid,valve means disposed in said well treating fluid outlet line betweensaid injection chamber and said well annulus, a pressure-imparting fluidinlet line interconnecting said pressure responsive means and apump-free source of pressure-imparting fluid, valve means disposed insaid pressure-imparting fluid inlet line between said pressureresponsive means and said source of pressure-imparting fluid, apressureimparting fluid outlet line connected to said pressure re sponsemeans and to said well treating fluid outlet line external of saidcontainer means, whereby said well treating fluid is contacted with apressure-imparting fluid and is thereby urged toward said well annulus,fluid pressure relief means connected to said pressure responsive meanswhereby pressure-imparting fluid in contact with said pressureresponsive means can be moved out of contact therewith so as to reducepressure imparted to said pressure responsive means, and timer meansinterconnected to said valve means and to said fluid pressure reliefmeans and adapted to intermittently activate the same, wherebyintermittent injection of a predetermined volume of said well treatingfluid into said annulus is effected, said fluid pressure relief meanscomprising a fluid bypass line interconnected with saidpressure-imparting fluid inlet line through said valve means in saidpressure-imparting fluid inlet line and interconnected with saidpressure-imparting fluid outlet line by valve means in communicationwith said pressure-imparting fluid outlet line, wherebypressure-imparting fluid can be passed from contact with said pressureresponsive means by drainage into said well.

4. The apparatus of claim 3 wherein said apparatus is adapted to operatewith water as said pressureimparting fluid, wherein said valve means incommunication with said pressure-imparting fluid outlet line is disposedin a common line into which said pressure-imparting fluid outlet lineand said well treating fluid outlet line merge.

5. Improved oil well treating apparatus adapted to be operated at apressure lower than that of the annulus of a well to which saidapparatus is to be connected, which apparatus comprises, in combination,container means which includes a single variable volume well treatingfluid injection chamber, pressure responsive means forming a part ofsaid chamber in said container means and adapted to vary the volume ofsaid container in response to pressure variations, a well treating fluidsupply line interconnecting said injection chamber and a well treatingfluid source, valve means controlling the passage of well treating fluidfrom said source to said injection chamber, a well treating fluid outletline interconnecting said chamber and the annulus of the well to betreated with said well treating fluid, valve means disposed in said welltreating fluid outlet line between said injection chamber and said wellannulus, a pressure-imparting fluid inlet line interconnecting saidpressure responsive means and a pump-free source of pressure-impartingfluid, valve means disposed in said pressure-imparting fluid inlet linebetween said pressure responsive means and said source ofpressure-imparting fluid, a pressure-imparting fluid outlet lineconnected to said pressure responsive means and to said well treatingfluid outlet line external of said container means, whereby said welltreating fluid is contacted with a pressure-imparting fluid and isthereby urged toward said well annulus, fluid pressure relief meansconnected to said pressure responsive means whereby pressure-impartingfluid in contact with said pressure responsive means can be moved out ofcontact therewith so as to reduce pressure imparted to said pressureresponsive means, and timer means interconnected to said valve means andto said fluid pressure relief means and adapted to intermittentlyactivate the same whereby intermittent injection of a predeterminedvolume of said well treating fluid into said annulus is effected,pressure equalizing container means connected to a common line merged tosaid pressure-imparting fluid outlet line and said well treating fluidoutlet line, an exit line disposed between said pressure equalizingcontainer means and said annulus of said well valve means disposed insaid exit line, whereby pressure between said well annulus and saidpressure equalizing container means can be equalized and whereby passageof a mixture of said well treating fluid and said pressure-impartingfluid into said well annulus is facilitated.

6. The improved apparatus of claim 5 wherein said apparatus is adaptedto operate with water as pressureimparting fluid and wherein said fluidpressure relief means comprises a relief line connected to said valveI12 and said pressure-imparting fluid inlet line and exposed to theatmosphere, whereby water can be drained from contact with said pressureresponsive means through said pressure-imparting fluid inlet line andassociated valve means and out of said apparatus through said reliefline.

References Cited by the Examiner UNITED STATES PATENTS 2,529,028 11/50Landon 10344 2,773,551 12/56 Warden et al. 166-l 2,843,206 7/58 McNamaral661 2,884,067 4/59 M-arken 1661 15 BENJAMIN HERSH, Primary Examiner.

1. IMPROVED OIL WELL TREATING APPARATUS, WHICH APPARATUS COMPRISES, INCOMBINATION, CONTAINER MEANS WHICH INCLUDES A SINGLE VARIABLE VOLUMEWELL TREATING FLUID INJECTION CHAMBER, PRESSURE RESPONSIVE MEANS FORMINGA PART OF SAID CHAMBER IN SAID CONTAINER MEANS AND ADAPTED TO VARY THEVOLUME OF SAID CHAMBER IN RESPONSE TO PRESSURE VARIATIONS, A WELLTREATING FLUID SUPPLY LINES INTERCONNECTING SAID INJECTION CHAMBER AND AWELL TREATING FLUID SOURCE, VALVE MEANS CONTROLLING THE PASSAGE OF WELLTREATING FLUID FROM SAID SOURCE TO SAID INJECTION CHAMBER, A WELLTREATING FLUID OUTLET LINE INTERCONNECTING SAID CHAMBER AND THE ANNULUSOF A WELL TO BE TREATED WITH SAID WALL TREATING FLUID, VALVE MEANSDISPOSED IN SAID WELL TREATING FLUID OUTLET LINE BETWEEN SAID INJECTIONCHAMBER AND SAID WELL ANNULUS, A FIRST PRESSURE-IMPARTING FLUID INLETLINE INTERCONNECTING SAID PRESSURE RESPONSIVE MEANS AND A PUMP-FREESOURCE OF PRESSURE-IMPARTING FLUID EXTERNAL OF SAID WALL, VALVE MEANSDISPOSED IN SAID FIRST PRESSURE IMPARTING FLUID INLET LINE BETWEEN SAIDPRESSURE RESPONSIVE MEANS AND SAID SOURCE OF PRESSURE-IMPARTING FLUID, APRESSURE-IMPARTING FLUID OUTLET LINE CONNECTED TO SAID PRESSURERESPONSIVE MEANS AND FLUID PRESSURE RELIEF MEANS CONNECTED TO SAIDPRESSURE RESPONSIVE MEANS WHEREBY PRESSURE-IMPARTING FLUID IN CONTACTWITH SAID PRESSURE RESPONSIVE MEANS DCAN BE MOVED OUT OF CONTACTTHEREWITH SO AS TO REDUCE PRESSURE IMPARTED TO SAID PRESSURE RESPONSIVEMEANS, A SECOND PRESSURE-IMPARTING FLUID INLET LINE INTERCONNECTING APUMP-FREE SOURCE OF FLUID PRESSURE AND SAID WALL TREATING FLUID OUTLETLINE EXTERNAL OF SAID CONTAINER MEANS, WHEREBY SAID WELL TREATING FLUIDIS CONTACTED WITH PRESSURE-IMPARTING FLUID AND AIS THEREBY URGED TOWARDSAID WELL ANNULUS, AND VALVE MEANS DISPOSED IN SAID SECONDPESSURE-IMPARTING FLUID INLET LINES, AND TIME MEANS MEANS INTERCONNECTEDTO SAID VALVE MEANS AND TO SAID FLUID PRESSURE RELIEF MEANS AND ADAPTEDTO INTERMITTENTLY ACTIVATE THE SAME, WHEREBY THE INTERMITTENT INJECTIONOF A PREDETERMINED VOLUME OF SAID WELL TREATING FLUID INTO SAID ANNULUSIS EFFECTED.